<template>
  <div>
    {{ num }}
    <MyCom1 :a.sync="num" :b.sync="num2" />
    <!-- <MyCom1 :a="num" @update:a="val=>num=val"/> -->
    <!-- <MyCom1 v-model="num" /> -->
    <!-- <MyCom1 :value="num" @input="val=>num=val" /> -->
  </div>
</template>
<script>
import MyCom1 from './MyCom1.vue'
export default {
  components: { MyCom1 },
  data() {
    return {
      num: 100,
      num2: 100
    }
  },
  methods: {
    f() {
      alert('f')
    }
  }
}
</script>
